Burger King / service/availability of product

Stopped at the Burger King on the Ohio Turnpike eastbound on June 3 at the Commodore Perry Travel Plaza at 10a.m. Ordered a Whopper. Sign states they are served beginning at 8.a.m. (see photo). Was told they are not available until 10:30.
Manager said the sign was incorrect.

Why have it on the sign.
I left without getting anything as did several other customers.